1. Field of the Invention
The present invention relates to cover structures of electronic devices and methods of manufacturing such cover structures, and particularly to a cover structure of an electronic device that has a plastic substrate and a method of manufacturing such cover structure.
2. Description of the Related Art
At present, plastic covers of electronic devices such as mobile phones generally comprise metal layers deposited on the plastic cover by plastic electroplating to obtain a decorative metallic appearance.
However, plastic electroplating can generally only deposit inert metals such as copper. Reactive metals such as aluminum can be deposited only with great difficulty. Furthermore, plastic electroplating is relatively complicated, resulting in unduly long processing times and unduly high costs.
To endeavor to overcome the foregoing drawbacks, U.S. Pat. No. 5,660,934 discloses a thermal spraying process for coating plastic articles with metal. However, the metal layer formed on the plastic article is easily eroded because it is directly exposed to the external environment. Furthermore, the metal layer has just a single color. This does not satisfactorily cater for consumer demand for a wide variety of aesthetically pleasing colors and designs.
Hence it is desired to provide a cover structure of an electronic device and a method of manufacturing the cover structure which can overcome the foregoing drawbacks of the related art.
A main object of the present invention is to provide a cover structure for an electronic device which has a metallic appearance with decorative colors or patterns.
Another object of the present invention is to provide a cover structure for an electronic device which resists corrosion.
A further object of the invention is to provide a method of manufacturing a cover structure for an electronic device which has a metallic appearance with decorative colors or patterns and which resists corrosion.
To achieve the above objects, a cover structure for an electronic device of the present invention includes a plastic cover, an aluminum or aluminum alloy layer on the plastic cover and an oxide layer of aluminum or aluminum alloy on the aluminum or aluminum alloy layer. A method of manufacturing the cover structure includes the steps of: (1) injection molding the plastic cover; (2) forming the aluminum or aluminum alloy layer on the plastic cover; and (3) anodizing the aluminum or aluminum alloy layer to form an oxide layer thereof.
The method also can include a step of coloring the oxide layer of aluminum or aluminum alloy. The cover structure thus formed has a metallic appearance with decorative colors or patterns, and is resistant to corrosion. The cover structure is not only very aesthetically pleasing to users but also durable.